Improvement in core-barrel



waited mes @sind dtjitlw.

ROBERT CAR'DWRIGHT, 0F CHICAGO, ILLINOIS.

Letters Patent No. 102,220, dated April 26, 1870.

IMPROVEMENT IN CORE-BARREL.

The Schedule referred to in these Letters Patent and making part of thesame To all fwhom it may concern Be it known that I, ROBERT CARTWRIGHT,of Chicago, in the county of Cook, in the State of Illinois,haveinvented anew and Improved Core-Barrel for Casting Cylinders orPipes; and I do hereby declare that the following is a full and exactdescription thereof, reference being had to the accompanying drawingsand to the letters of reference marked thereon.

The nature of my invention consists in making a core-barrel composed ofstaves or sections fastened to a center frame, so constructed that itcan be readily removed after casting is poured, and also made so thatthe core .can be set central in the mold, producing thereby uniform,thickness of metal in the castmg.

To enable others skilled in the 4alt to make and use my invention, Iwill proceed to describe its construction and operation.

Figure l is a longitudinal section of core-barrel and mol Figure 2 is aplan section of core-barrel in detail.

I construct the center spider by having a hollow shaft, A, bored out atlower end to fit a center spindle or shaft, B, said shaft B beingfastened into a vbase-plate or spider, C, set on brick-work.

like rim D, though enough larger in diameter so that the smallestdiameter of the couic section shall be larger than the largest diameterof the conic section .of the rim D, thus allowing the rim D to be drawnout through the seat of the rim E in removing the core from thecasting.V

I then make sections or staves F, of suitable size to admit of a coat orcovering of loam on their out. side surface to form the diameter of'core required.

The staves F have projections corresponding to the conio section ortaper of the rims D and E, either cast or bolted on their internal ends.

The staves F F are held to `the center spidersby means of bolts I,which, when fastened, hold the staves securely together to the rims,thus forming a barrel or cylinder.

The staves F are strengthened by ribs internally, and are perforatedwith small holes to allow the escape of the gas consequent to allcastings. 'lhey also have their external surfaces roughened by means ofsmall teats or projections raised upon them, to serve as holding pointsfor the loam coating.

Intermediate between the ltwo ends of the staves IA place a series ofbraces, G, which are of such length as to wedge or jam between thestaves and center shaft .to give the requisite diameter .of core.

v placed in core-oven to dry.

A. These, when placed iu position, are set a little the highest at theend, resting against center shaft A, and connected by chains or rods totop spider E.

Being thus attached and at such an angle, they are easily relieved whenthe center shaft and spiders are withdrawn, after 'castingis poured, andcome away with them, leaving the staves in the casting.

'lhe staves comprising the barrel are made as shown by drawing, iig. 2,with their sides and ends so shaped thttit allows of stave No. l beingi-rst drawn inwardly by means of crane hooked into ring I-I, andafterwards No. 2, No. 3, Sto., until all are removed, leaving thecasting to cool and shrink without any danger of .its being altered inshape or in soundness, as it is entirely free on its inner surface.

J J are clamps holding the core barrel in the mold to prevent lifting,under the head of ferrostatic pressure.

I I are bolts fastening staves F to rims D and E.

K K are hanging-rods so placed as to transmit the strain ldue to greatweight of staves to the center shaft, thus enabling me to obtaingreatest Strength with less weightvof material.

N is a clevis, by means of which thc core-barrel is handled in theoperation of making the corev and castings.

@L L'is section. of a cylinder in the mold.

In order that my invention may be more readilyl understood, I willproceed to describe its operation.

'Io prepare the mold or cope I first place upon the center shaft B, andfitting it nicely, two cross-bars, one near the top and one at thebottom. On the outer end of these, and set to requisite distance forgiven diameter of mold, I'fasten a sweep strike or board. 'lheloam isthen daubed on the brick cope, and the sweep is turned around the shaftas a center, said shaft being properly stayed at top to insure its beingcentral and firm. ,'lhe sweep thus performs its work of striking theloam mold perfectly cylindrical. After this is done the mold is dried bya furnace placed in the well M, at bottom. When dry it is ready for thecore. The core is made by placing the barrel upright on a pivot fittedinto lower end of shaft A, and being firmly guidedat top to admit ofbeing turned around on said pivot. In its revolutions it is set-at suchaknown distance from a sweep strike or board as The loam is then daubedon the barrel` as it is slowly revolved, and the strike-board or sweepscrapes it to a uniform surface and diameter. When its surface is allcomplete the core-barrel i'slifted, by means of the clevis N, and rIhemold and core being thoroughly dried and blackwashed, the core is set inVplace by the shaft A being slipped over shaft B and lowered into itsplace. As the mold has been struck from the shaft B as as a center, andthe core being struck with A as a center, the space between them must,in consequence, be perfectly uniform and equal. When the core is set inplace the space between the cope and core (tbe mold proper,) is coveredby a plate, O, covered with loam on its underside, and having a numberof holes, P, through which the iron is poured into the mold from asurrounding runner. After the casting is poured the bolts I are drivenout of rims D and E, and the clamps J are removed. When this is done thecrane is hooked into clevis N, and the center shaft A, with its rims Dand E and attached braces G, are drawn out, leaving the staves F in thecasting. Stave No. 1, with the parallel end, is first removed, and then,successively, Nos. 2, 3, &c.

What I claim as my invention, and desire to secure by Letters Patent,is-

l. lhe hollow center shaft A, in combination with the center shaft B,-substantially as described, and for 4the purposes set forth.

2. The spider and Iims D and E, in combination with the center shaft A,substantially as described,"

Witnesses T. E. SICKELS, WM. M. MERRICK.

